Rewrote error logging code

- The new error logging only creates one log per error and has context
with the error if specified.
- Any duplicate lines in error stacktrace are not taken into account
when hashing to avoid recursive function errors being logged in different
files

Affects issues:
- Close #1246

Plan/common/src/main/java/com/djrapitops/plan/delivery/webserver/WebServer.java

@@ -17,8 +17,6 @@
 package com.djrapitops.plan.delivery.webserver;
 
 import com.djrapitops.plan.SubSystem;
-import com.djrapitops.plan.identification.ServerInfo;
-import com.djrapitops.plan.identification.properties.ServerProperties;
 import com.djrapitops.plan.settings.config.PlanConfig;
 import com.djrapitops.plan.settings.config.paths.PluginSettings;
 import com.djrapitops.plan.settings.config.paths.WebserverSettings;
@@ -57,8 +55,7 @@ public class WebServer implements SubSystem {
     private final PlanFiles files;
     private final PlanConfig config;
 
-    private final ServerProperties serverProperties;
-    private Addresses addresses;
+    private final Addresses addresses;
     private final RequestHandler requestHandler;
 
     private final PluginLogger logger;
@@ -75,7 +72,6 @@ public class WebServer implements SubSystem {
             Locale locale,
             PlanFiles files,
             PlanConfig config,
-            ServerInfo serverInfo,
             Addresses addresses,
             PluginLogger logger,
             ErrorHandler errorHandler,
@@ -84,7 +80,6 @@ public class WebServer implements SubSystem {
         this.locale = locale;
         this.files = files;
         this.config = config;
-        this.serverProperties = serverInfo.getServerProperties();
         this.addresses = addresses;
 
         this.requestHandler = requestHandler;

Plan/common/src/main/java/com/djrapitops/plan/modules/APFModule.java

@@ -17,6 +17,7 @@
 package com.djrapitops.plan.modules;
 
 import com.djrapitops.plan.PlanPlugin;
+import com.djrapitops.plan.utilities.logging.ErrorLogger;
 import com.djrapitops.plugin.IPlugin;
 import com.djrapitops.plugin.benchmarking.Timings;
 import com.djrapitops.plugin.command.ColorScheme;
@@ -70,8 +71,8 @@ public class APFModule {
 
     @Provides
     @Singleton
-    ErrorHandler provideErrorHandler(IPlugin plugin) {
-        return plugin.getErrorHandler();
+    ErrorHandler provideErrorHandler(ErrorLogger errorLogger) {
+        return errorLogger;
     }
 
     @Provides

Plan/common/src/main/java/com/djrapitops/plan/storage/file/PlanFiles.java

@@ -59,7 +59,7 @@ public class PlanFiles implements SubSystem {
     }
 
     public Path getCustomizationDirectory() {
-        return dataFolder.toPath().resolve("web");
+        return getDataDirectory().resolve("web");
     }
 
     public File getLogsFolder() {
@@ -72,6 +72,10 @@ public class PlanFiles implements SubSystem {
         }
     }
 
+    public Path getLogsDirectory() {
+        return getDataDirectory().resolve("logs");
+    }
+
     public File getConfigFile() {
         return configFile;
     }

Plan/common/src/main/java/com/djrapitops/plan/utilities/java/Lists.java

@@ -19,6 +19,7 @@ package com.djrapitops.plan.utilities.java;
 import java.util.*;
 import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
 
 /**
  * Methods that can be used as functional interfaces when dealing with Maps.
@@ -35,6 +36,10 @@ public class Lists {
         return new ArrayList<>();
     }
 
+    public static <V> Lists.Builder<V> builder(Class<V> ofType) {
+        return new Lists.Builder<>();
+    }
+
     /**
      * Efficient replacement for List#stream().filter(keep).collect(Collectors.toList()).
      *
@@ -85,4 +90,30 @@ public class Lists {
         }
         return mapped;
     }
+
+    public static class Builder<V> {
+        private final List<V> list;
+
+        private Builder() {
+            list = new ArrayList<>();
+        }
+
+        public Lists.Builder<V> add(V value) {
+            list.add(value);
+            return this;
+        }
+
+        public Lists.Builder<V> addAll(Collection<V> values) {
+            list.addAll(values);
+            return this;
+        }
+
+        public Lists.Builder<V> apply(UnaryOperator<Lists.Builder<V>> operator) {
+            return operator.apply(this);
+        }
+
+        public List<V> build() {
+            return list;
+        }
+    }
 }

Plan/common/src/main/java/com/djrapitops/plan/utilities/logging/ErrorContext.java

@@ -0,0 +1,77 @@
+/*
+ *  This file is part of Player Analytics (Plan).
+ *
+ *  Plan is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License v3 as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Plan is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with Plan. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.djrapitops.plan.utilities.logging;
+
+import java.util.*;
+
+/**
+ * Contains context for an error that might help debugging it.
+ *
+ * @author Rsl1122
+ */
+public class ErrorContext {
+
+    private final List<Object> related;
+    private String whatToDo;
+
+    private ErrorContext() {
+        related = new ArrayList<>();
+    }
+
+    public static ErrorContext.Builder builder() {
+        return new ErrorContext.Builder();
+    }
+
+    public Optional<String> getWhatToDo() {
+        return Optional.ofNullable(whatToDo);
+    }
+
+    public Collection<String> toLines() {
+        List<String> lines = new ArrayList<>();
+        for (Object o : related) {
+            lines.add(Objects.toString(o));
+        }
+        return lines;
+    }
+
+    public static class Builder {
+        private final ErrorContext context;
+
+        public Builder() {
+            context = new ErrorContext();
+        }
+
+        public Builder whatToDo(String whatToDo) {
+            context.whatToDo = whatToDo;
+            return this;
+        }
+
+        public Builder related(Object related) {
+            context.related.add(related);
+            return this;
+        }
+
+        public Builder related(Object... related) {
+            context.related.addAll(Arrays.asList(related));
+            return this;
+        }
+
+        public ErrorContext build() {
+            return context;
+        }
+    }
+}

Plan/common/src/main/java/com/djrapitops/plan/utilities/logging/ErrorLogger.java

@@ -0,0 +1,242 @@
+/*
+ *  This file is part of Player Analytics (Plan).
+ *
+ *  Plan is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License v3 as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Plan is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with Plan. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.djrapitops.plan.utilities.logging;
+
+import com.djrapitops.plan.PlanPlugin;
+import com.djrapitops.plan.delivery.formatting.Formatters;
+import com.djrapitops.plan.identification.properties.ServerProperties;
+import com.djrapitops.plan.storage.file.PlanFiles;
+import com.djrapitops.plan.utilities.java.Lists;
+import com.djrapitops.plan.version.VersionChecker;
+import com.djrapitops.plugin.logging.L;
+import com.djrapitops.plugin.logging.console.PluginLogger;
+import com.djrapitops.plugin.logging.error.ErrorHandler;
+import dagger.Lazy;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.commons.lang3.StringUtils;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * New logger that logs errors to specific files.
+ *
+ * @author Rsl1122
+ */
+@Singleton
+public class ErrorLogger implements ErrorHandler {
+
+    private final PlanPlugin plugin;
+    private final PluginLogger logger;
+    private final PlanFiles files;
+    private final Lazy<ServerProperties> serverProperties;
+    private final Lazy<VersionChecker> versionChecker;
+    private final Lazy<Formatters> formatters;
+
+    @Inject
+    public ErrorLogger(
+            PlanPlugin plugin,
+            PluginLogger logger,
+            PlanFiles files,
+            Lazy<ServerProperties> serverProperties,
+            Lazy<VersionChecker> versionChecker,
+            Lazy<Formatters> formatters
+    ) {
+        this.plugin = plugin;
+        this.logger = logger;
+        this.files = files;
+        this.serverProperties = serverProperties;
+        this.versionChecker = versionChecker;
+        this.formatters = formatters;
+    }
+
+    public void log(L level, Throwable throwable, ErrorContext context) {
+        String errorName = throwable.getClass().getSimpleName();
+        String hash = hash(throwable);
+        Path logsDir = files.getLogsDirectory();
+        Path errorLog = logsDir.resolve(errorName + "-" + hash + ".txt");
+        if (Files.exists(errorLog)) {
+            logExisting(errorLog, throwable, context);
+        } else {
+            logNew(errorLog, throwable, context);
+        }
+        logToConsole(level, errorLog, throwable, context);
+        if (L.CRITICAL == level) {
+            plugin.getPluginLogger().error("CRITICAL error triggered a plugin shutdown.");
+            plugin.onDisable();
+        }
+    }
+
+    private void logExisting(Path errorLog, Throwable throwable, ErrorContext context) {
+        // Read existing
+        List<String> lines;
+        try (Stream<String> read = Files.lines(errorLog)) {
+            lines = read.collect(Collectors.toList());
+        } catch (IOException e) {
+            logAfterReadError(errorLog, throwable, context);
+            return;
+        }
+        int occurrences = getOccurrences(lines) + 1;
+        List<String> newLines = buildNewLines(context, lines, occurrences);
+        overwrite(errorLog, throwable, newLines);
+    }
+
+    private void overwrite(Path errorLog, Throwable throwable, List<String> newLines) {
+        try {
+            Files.write(errorLog, newLines, StandardOpenOption.TRUNCATE_EXISTING);
+        } catch (IOException e) {
+            throwable.addSuppressed(e);
+            Logger.getGlobal().log(Level.SEVERE, "Failed to log Plan error, see suppressed.", throwable);
+        }
+    }
+
+    private List<String> buildNewLines(ErrorContext context, List<String> lines, int occurrences) {
+        Lists.Builder<String> builder = Lists.builder(String.class)
+                .add("Last occurred: " + getTimeStamp() + " Occurrences: " + occurrences);
+        // 5 contexts are enough.
+        if (occurrences <= 5) {
+            builder = buildContext(context, occurrences, builder);
+        }
+        int lineCount = lines.size();
+        int firstContextLineIndex = findFirstContextLine(lines, lineCount);
+        return builder.addAll(lines.subList(firstContextLineIndex, lineCount))
+                .build();
+    }
+
+    private String getTimeStamp() {
+        return formatters.get().iso8601NoClockLong().apply(System.currentTimeMillis());
+    }
+
+    private Lists.Builder<String> buildContext(ErrorContext context, int occurrences, Lists.Builder<String> builder) {
+        return builder.add("---- Context " + occurrences + " ----")
+                .add("Plan v" + versionChecker.get().getCurrentVersion())
+                .add(serverProperties.get().getName() + " " + serverProperties.get().getVersion())
+                .add("Server v" + serverProperties.get().getImplVersion())
+                .add("")
+                .addAll(context.toLines())
+                .add("");
+    }
+
+    private void logAfterReadError(Path errorLog, Throwable throwable, ErrorContext context) {
+        logger.error("Failed to read " + errorLog + " deleting file");
+        try {
+            Files.deleteIfExists(errorLog);
+        } catch (IOException ioException) {
+            logger.error("Failed to delete " + errorLog);
+        }
+        logNew(errorLog, throwable, context);
+    }
+
+    private int getOccurrences(List<String> lines) {
+        String occurLine = lines.get(0);
+        return Integer.parseInt(StringUtils.splitByWholeSeparator(occurLine, ": ")[2].trim());
+    }
+
+    private int findFirstContextLine(List<String> lines, int lineCount) {
+        int firstContextLineIndex = 0;
+        for (int i = 0; i < lineCount; i++) {
+            if (lines.get(i).contains("---- Context")) {
+                firstContextLineIndex = i;
+                break;
+            }
+        }
+        return firstContextLineIndex;
+    }
+
+    private void logToConsole(L level, Path errorLog, Throwable throwable, ErrorContext context) {
+        String errorName = throwable.getClass().getSimpleName();
+        String errorMsg = throwable.getMessage();
+        String errorLocation = errorLog.toString();
+        logger.log(level,
+                "Ran into " + errorName + " - logged to " + errorLocation,
+                "(INCLUDE CONTENTS OF THE FILE IN ANY REPORTS)",
+                context.getWhatToDo().map(td -> "What to do: " + td).orElse("Error msg: \"" + errorMsg + "\"")
+        );
+    }
+
+    private void logNew(Path errorLog, Throwable throwable, ErrorContext context) {
+        List<String> stacktrace = buildReadableStacktrace(throwable);
+        List<String> lines = Lists.builder(String.class)
+                .add("Last occurred: " + getTimeStamp() + " Occurrences: 1")
+                .apply(builder -> this.buildContext(context, 1, builder))
+                .add("---- Stacktrace ----")
+                .addAll(stacktrace)
+                .build();
+        writeNew(errorLog, throwable, lines);
+    }
+
+    private void writeNew(Path errorLog, Throwable throwable, List<String> lines) {
+        try {
+            Files.createDirectories(errorLog.getParent());
+            Files.write(errorLog, lines, StandardOpenOption.CREATE_NEW, StandardOpenOption.APPEND);
+        } catch (IOException e) {
+            throwable.addSuppressed(e);
+            Logger.getGlobal().log(Level.SEVERE, "Failed to log Plan error, see suppressed.", throwable);
+        }
+    }
+
+    @Override
+    @Deprecated
+    public void log(L level, Class caughtBy, Throwable throwable) {
+        log(level, throwable, ErrorContext.builder()
+                .related("Caught by " + caughtBy.getName())
+                .build());
+    }
+
+    private String hash(Throwable e) {
+        StringBuilder seed = new StringBuilder();
+        Throwable cause = e;
+        Set<String> alreadyPresent = new HashSet<>();
+        while (cause != null) {
+            for (StackTraceElement element : cause.getStackTrace()) {
+                String asLine = element.toString();
+                if (!alreadyPresent.contains(asLine)) {
+                    seed.append(asLine);
+                }
+                alreadyPresent.add(asLine);
+            }
+            cause = e.getCause();
+        }
+        return DigestUtils.sha256Hex(seed.toString()).substring(0, 10);
+    }
+
+    private List<String> buildReadableStacktrace(Throwable e) {
+        List<String> trace = new ArrayList<>();
+        trace.add(e.toString());
+        for (StackTraceElement element : e.getStackTrace()) {
+            trace.add("   " + element);
+        }
+        Throwable cause = e.getCause();
+        if (cause != null) {
+            trace.add("Caused by:");
+            trace.addAll(buildReadableStacktrace(cause));
+        }
+        return trace;
+    }
+}

Plan/common/src/main/resources/assets/plan/bungeeconfig.yml

@@ -15,7 +15,7 @@ Plugin:
     Create_new_locale_file_on_next_enable: false
     Debug: false
     Dev: false
-    Delete_logs_after_days: 2
+    Delete_logs_after_days: 7
   Update_notifications:
     # Display update notification on the website
     Check_for_updates: true

Plan/common/src/main/resources/assets/plan/config.yml

@@ -14,7 +14,7 @@ Plugin:
     Create_new_locale_file_on_next_enable: false
     Debug: false
     Dev: false
-    Delete_logs_after_days: 2
+    Delete_logs_after_days: 7
   Update_notifications:
     # Display update notification on the website
     Check_for_updates: true